1. Field of the Invention
The invention relates to a cooling system comprising a heat sink having a first contact zone and a second contact zone, which are configured to absorb a first heat flow from a first component and a second heat flow from a second component, and a first transmission means for transmission of the first heat flow through the first contact zone into the heat sink. The invention also relates to a cold plate having a first contact zone, and a second contact zone, configured for absorbing a first heat flow from a first component and a second heat flow from a second component.
The invention also relates to an electrical assembly having a printed circuit board, where the assembly included the cooling system.
2. Description of the Related Art
Due to the miniaturization of electronic components, a higher packing density/functional density is increasingly being provided by electronic components/parts on a printed circuit board assembly, such as a populated printed circuit board. This leads to an increase in the power loss, because the appliance functionality, and therefore the number of electronic components used, increase.
The use of microprocessors with higher clock rates is also leading to an increase in the power loss. Here, the developers of electronic components and printed circuit board assemblies are faced with the following problem with regard to optimization of the options for use and therefore the economy: increasing the power loss per assembly because of increasing packing densities and faster microprocessors, while simultaneously minimizing the appliance dimensions. This is leading to a more than proportional increase in the power loss density which, in the case of electronic assemblies, is defined as the power loss per unit volume. Consequently, there is a requirement to develop improved concepts, in the sense of the thermal power loss to be dissipated for heat dissipation from electronic assemblies, with the simultaneous optimum use of space.
In accordance with conventional technologies, thermal contact is made with electronic components on a cold plate, a heat sink or housing parts for this purpose. The heat can then be dissipated from the heat-emitting electronic component by free or forced convection into the heat sink and from the heat sink into the surrounding air.
In many electronic assemblies or appliances, there is a requirement for space and cost reasons to make thermal contact between a plurality of electronic components and a common cooling system.
EP 0 454 603 A2 discloses a cooling system in which thermal contact is made with a plurality of chips by a first flexible insert, in the form of a rib. A grid structure with obliquely positioned spring arms is fitted to the first flexible insert, and a second flexible insert is fitted to this grid structure and makes thermal contact with an upper shell of the cooling system, with the upper shell being firmly screwed to a lower shell of the cooling system. This solution has the disadvantage that three transmission means must be arranged between a heat-emitting component and a cold plate for use on a printed circuit board.
Making contact between a plurality of electronic components and a common cold plate is subject to the problem that the dimensional tolerances which the electronic components have mean that optimum thermal contact cannot be made at the same time between the cold plate and all the electronic components. For example, two electronic components that are arranged on a printed circuit board have a different height difference, which must be thermally bridged. This is normally achieved by use of a thermal interface material (TIM). Although this material, which compensates for the height difference, bridges the thermal heat dissipation path, it is not, however, optimally designed.